1. Field of the Invention
The invention relates generally to the design of slip elements that are used in gripping systems for downhole tools.
2. Description of the Related Art
Numerous downhole tools incorporate gripping systems that use one or more slips. The slips are moved radially outwardly against a surrounding tubular member in order to resist axial or torsional forces, or both. In many instances, slips are set to securely anchor a downhole tool in place within a surrounding tubular member. In other cases, such as with drag blocks, a slip may be set to merely resist axial or torsional movement. Downhole tools that incorporate gripping systems that use slips include, but are not limited to, packers, anchors, plugs, setting tools, bridge plugs, locks and fishing tools. Plugs, for example, have a plug body with slip elements that can be selectively moved radially outwardly to bitingly engage a surrounding tubular member. One type of plug is described in U.S. Pat. No. 6,167,963 issued to McMahan et al. That patent is owned by the assignee of the present application and is incorporated herein by reference.
Often, a downhole tool will need to be removed after it has been set, and this is usually done by milling through the tool. Unfortunately, milling through most conventional tool designs is costly and leaves large pieces which may be difficult to circulate out of the flowbore.